This invention relates to a method for controlling a copying apparatus which is adapted to print images on opposite surfaces of a copy sheet.
In this type of copying apparatus, an image of an original is first printed on one surface of a copy sheet in a usual copying process (by transfer printing and fixing), and such copy sheet is returned to an original sheet feeding device or diverted to a second sheet feeding device by actuating single-surface/double-surface copying switching means (such as a switching guide plate) mounted in a duplicate copy ejecting passage, so that the copy sheet is turned inside out and fed to a copying station again to print an image on the other surface or under side thereof.
When this type of copying apparatus is used for copying several continuous pages or the whole pages of a book original, difficulties are encountered in producing a bundle or bundles of duplicate copies of the desired pages of the book original which has the same order and arrangement of pages as the book original. There are three factors concerned in the occurrence of these difficulties, such three factors being complicated and involved with one another.
The first factor is the construction of a book original itself. Since the pages of a book cannot be separated into discrete sheets, a book original must be opened at desired pages and the pages must be turned manually when copying is carried out like a sheet original, a book original has top and bottom, so that copying of pages on opposite surfaces of a copy sheet should be carried out in such a manner that no pages are copied upside down. Also, there are two types of binding in a book original or a right-side binding and a left-side binding [See FIGS. 1(a) and 1(b)]. A book original is arranged in the order of pages, so that copying must be carried out by accurately following the pages and there should be no confusion in the order in which the pages are copied. Since a book original has binding allowances in the adjacent edge portions of the continuous two pages, a copy sheet having continuous pages of a book original printed on opposite surfaces thereof must have its binding allowances on the same edge side of the opposite surfaces of the copy sheet.
The second factor is the construction of a copying apparatus itself. In a copying apparatus of the type which is generally referred to as a slit-exposure type copying apparatus, a photosensitive member of the copying apparatus is exposed to an optical image of a book original by scanning the book original, which is placed on an original placing plate, by a light flux moved from one end of the original placing plate to the other end thereof or in one direction. Therefore, when it is desired to illuminate at all times the second page of the two pages of a book original placed on the original placing plate, it is necessary either to turn the book original upside down depending on whether the book original to be copied is bound on the right side or on the left side, or to slightly move the book original manually after the pages thereof are placed on the original placing plate. When a book original is handled in this way, there is the danger that confusion is caused in the order of pages to be printed. In a copying apparatus adapted to print images on opposite surfaces of a copy sheet, switching means, as a switching guide plate, must be provided, so that switching between printing of an image only on one surface of a copy sheet and printing of images on opposite surfaces of a copy sheet can be effected by such switching means.
The third factor is a requirement which must be met when the operator performs printing of pages of a book original. The following four combinations come to mind with regard to the pages which are desired to be copied: [See page 4 or pages 5(a) to 5(d) ]:
(1) A combination in which an initial page is an odd number and a terminating page is also an odd number (odd-odd);
(2) A combination in which an initial page is an odd number and a terminating page is an even number (odd-even);
(3) A combination in which an initial page is an even number and a terminating page is an odd number (even-odd); and
(4) A combination in which an initial page is an even number and a terminating page is also an even number (even-even).
When it is desired to copy a diagram or illustration of a book original, such diagram or illustration may spread over the two adjacent pages of the open book original. When this is the case, one portion of the diagram or illustration should be copied on the underside of a preceding copy sheet and the other portion thereof should be copied on the upper surface of the next following copy sheet.
Heretofore, proposal has been made to overcome the aforementioned difficulties by using a copying apparatus wherein the original placing glass plate is divided into two sections, one section being adapted to receive thereon an odd number page of a book original and the other section being adapted to receive thereon an even number page thereof. However, when this type of copy apparatus is used, open pages of a book original should be illuminated separately, and the movement of the scanner must start at the bound portion of a book original. This results in the apparatus becoming complex in construction. Moreover, the operation is troublesome because the manner in which a book original is placed on the original placing glass plate with respect to its top and bottom should be reversed depending on whether the book original to be handled is bound on the right side or on the left side. Moreover, no means is provided in this copying apparatus for arranging the printed copy sheets in an orderly manner when continuous pages of a book original are copied in respect copying operations.